"We've gone on holiday by mistake," says Richard E Grant's Withnail in that wonderful black comedy Withnail and I, and one senses that Ross Brawn, the Mercedes team principal, feels rather the same way.

While the summer sabbatical feels like a lifesaver for many in the hectically scheduled, vroom and bust world of Formula One, its timing was less than ideal for a Mercedes team that appeared to be gathering a menacing momentum in the weeks leading up to the break.

Lewis Hamilton and Nico Rosberg are the strongest drivers' pairing in the paddock. And now that they have the quickest car too, at least over one lap, they look the most likely to threaten Red Bull's hegemony in the second half of the season.

In fourth place, 48 points behind Vettel with nine races to go, he may look like an outsider but at his best, and when given the right equipment, Hamilton is too much of a handful for anyone, including the current world champion.

His difficulty will be in matching Vettel's staggering level of consistency, but the next three tracks glitter with promise for him. The fast Spa-Francorchamps circuit, with some of the best corner sections in the sport, is a drivers' track, and no one drives quite like Hamilton, who won here in 2010.

"I'm really looking forward to the second half; that is usually my favourite part," he says. "I can honestly say I feel just so invigorated, it's so refreshing to be somewhere new. I hope there's a world championship somewhere ahead. That's what I'm working for every year, that's why I keep that discipline, that's why I train so much over the winter, that's why I wake up every day and train.

"That's why I put so much effort into travelling and that's why you sacrifice so many small things, certain things in your life, and so I hope at some stage I get that second world championship."

Brawn, too, is optimistic about the races ahead. "We'll have a much more respectable second half," he says. "We've scored more points already than we did last year, and we're just over halfway through. We've got a strong enough organisation to ensure we won't let it slip. We're on a journey here with Lewis and we don't know where the limits are."

Everyone, including Mercedes, will be taking a long hard look at the tyres at Spa. The new Pirelli tyre, a combination of the 2012 construction and the 2013 compound, uses Kevlar composite instead of steel in its construction. It added up to some cool running in Hungary. But the Hungaroring circuit is not dissimilar to Monaco in some respects. It is certainly not a representative track.

After Spa, where the tyres will be tested by higher lateral forces, we will all have a much better idea where these wheels are taking us. Red Bull, with Vettel enjoying a 38-point lead over second-placed Kimi Raikkonen, are still the team to beat, and they are unlikely to implode under pressure. Ferrari are expected to bring meaningful improvements to Spa, and they need to because they have been going backwards in recent races.

The fourth biggest team this year has been Lotus. Everyone says they have not got the money to keep up with the leading three teams, but Raikkonen's consistency has been remarkable.

The next few weeks will shape not only the two world championships but also the driver line-ups for next year, with Mark Webber's approaching retirement opening up a number of possibilities. The Red Bull seat is still likely to go to Daniel Ricciardo or Raikkonen, despite links with Fernando Alonso. But Alonso's team-mate, Felipe Massa, is under familiar pressure.

There will be no changes at Mercedes or McLaren, though Sergio Pérez's recent description of his McLaren car as "complicated, difficult and inconsistent" is not exactly what the team wanted to hear on their 50th anniversary.